Casing of a turbocharger

ABSTRACT

A casing of a turbocharger has a main body and a heat dissipating layer disposed on an outer surface of the main body. When heat inside the main body is conducted to the outer surface of the main body, the heat dissipating layer dissipates the heat quickly. Since the heat does not accumulate in the main body, temperature of the main body is low and the casing does not oxidize under high temperature. Therefore, the casing of the turbocharger has low manufacturing cost and is economical.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a casing of a turbocharger, especially to a casing of a turbocharger of a vehicle engine.

2. Description of the Prior Art(s)

An engine is the core of a vehicle. Increasing performance of the engine is necessary for improving overall performance of the vehicle. To increase the performance of the engine, more fuel and air should be fed into the engine. As more fuel is burned, more power is generated.

A conventional turbocharger comprises a compressing unit, a turbine unit, and a central shaft. The central shaft has two ends respectively connected to the compressing unit and the turbine unit. Exhaust gas discharged from the engine drives an impeller of the turbine unit such that the central shaft and an impeller of the compressing unit rotate accordingly. Thus, a great mass of air is compressed by the compressing unit and is fed to the engine to enhance the performance of the engine.

However, when the conventional turbocharger operates, a great deal of heat is generated such that temperature of the conventional turbocharger is raised. Since a casing of the conventional turbocharger is made of metal, the metal casing is oxidized easily under high temperature. In order to avoid oxidation, the casing of the conventional turbocharger may be anodized or may be made of heat resistant materials, such as ceramic material, composite material, heat resistant steel, or the like, but both of said technical means increase manufacturing cost of the casing and are not economical.

To overcome the shortcomings, the present invention provides a casing of a turbocharger to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide a casing of a turbocharger. The casing has a main body and a heat dissipating layer disposed on an outer surface of the main body.

When heat inside the main body is conducted to the outer surface of the main body, the heat dissipating layer dissipates the heat quickly. Since the heat does not accumulate in the main body, temperature of the main body is low and the casing does not oxidize under high temperature. Therefore, the casing of the turbocharger has low manufacturing cost and is economical.

Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view in partial section of a first embodiment of a casing of a turbocharger in accordance with the present invention;

FIG. 2 is an enlarged cross-sectional side view of the first embodiment of the casing in FIG. 1;

FIG. 3 is an enlarged cross-sectional side view of a second embodiment of a casing of a turbocharger in accordance with the present invention;

FIG. 4 is a schematic perspective view of an experimental apparatus for the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 to 3, a casing of a turbocharger in accordance with the present invention comprises a main body 10, 10A and a heat dissipating layer 20.

The main body 10, 10A is hollow and has an outer surface. With reference to FIG. 2, the outer surface of the main body 10 may be smooth. With reference to FIG. 3, the outer surface of the main body 10A may be rough.

The heat dissipating layer 20 is disposed on the outer surface of the main body 10, 10A, is coated on the outer surface of the main body 10, 10A and comprises multiple carbon nanocapsules (CNCs).

Specifically, the CNCs are mixed with aqueous based inorganic resins to form a fluid heat dissipating coating, wherein an amount of the CNCs is 2 weight percent (wt %) and an amount of the aqueous based inorganic resins is 98 wt % of the fluid heat dissipating coating. After the fluid heat dissipating coating is coated on the outer surface of the main body 10, 10A and is dried, the amount of the CNCs becomes 7 wt % of the dried heat dissipating coating. Moreover, a thickness of the dried heat dissipating coating, i.e. the heat dissipating layer 20, is 20 μm to 80 μm. Preferably, the thickness of the heating dissipating layer 20 is 50 μm.

With reference to FIG. 1, the turbocharger further has a compressing unit 30, a turbine unit 50 and a central shaft 40. The compressing unit 30, the turbine unit 50 and the central shaft 40 are all mounted in the casing. The central shaft 40 is disposed between the compressing unit 30 and the turbine unit 50 and has two ends respectively connected to the compressing unit 30 and the turbine unit 50. When an impeller 51 of the turbine unit 50 rotates, the central shaft 40 and an impeller 31 of the compressing unit 30 rotate accordingly. When the compressing unit 30, the turbine unit 50 and the central shaft 40 operate, a great deal of heat is generated. The heat is sequentially conducted to the main body 10, 10A and the heat dissipating layer 20, and then is dissipated from the heat dissipating layer 20.

Specifically, an experiment in heat dissipating effect of the heat dissipating layer 20 to the casing is carried out as follows.

A control group: a casing of a turbocharger without a heat dissipating layer, which is the same as the main body 10, 10A of the present invention.

An experimental group: the casing of the turbocharger in accordance with the present invention.

Experimental Procedures:

(1) With reference to FIG. 4, a thermocouple thermometer is provided. The casing is divided into an area A, an area B, and an area C. The thermocouple thermometer has multiple junctions respectively connecting to the area A, the area B, and the area C.

(2) Provide a heating device. The heating device comprises a jet burner 70 corresponding to an interior of the casing.

(3) Switch on the heating device to allow the jet burner 70 to continuously and steadily heat the casing, and measure and record beginning times and initial temperatures when temperatures of the area A, the area B and the area C of the casing begin rising.

(4) Switch off the heating device to stop heating the casing when the temperatures of the area A, the area B and the area C of the casing stop rising and the area A, the area B and the area C the casing achieve their respective highest temperatures.

Experiment Result: as Shown in Table 1.

TABLE 1 Control Group Experimental Group A B C A B C Beginning 15:24:26 15:24:26 15:24:26 13:47:09 13:47:09 13:47:09 Time of Temperature Rise (hh:mm:ss) Initial 37.5 36.5 39.5 38.0 58.3 34.5 Temperature of Temperature Rise (° C.) Time of 15:37:17 15:43:07 15:36:59 14:11:02 14:11:02 14:11:01 Achieving Highest Temperature (hh:mm:ss) Heating 00:12:51 00:18:41 00:12:33 00:23:53 00:23:53 00:23:52 Time (hh:mm:ss) Heating 12.85 18.68 12.55 23.88 23.88 23.86 Time (min) Highest 901.9 906.2 867.7 761.9 788.8 710.1 Temperature (° C.) Heating 67.3 46.5 66.0 30.3 30.6 28.3 Rate (° C./min) Average 59.9 29.7 Heating Rate (° C./min)

As shown in Table 1, the average heating rate of the control group is 59.9° C./min. The average heating rate of the experimental group is 29.7° C./min, which is slower than the average heating rate of the control group, and the two groups differ from each other by the heat dissipating layer 20 of the experimental group. When the casing of the experimental group is heated and the temperature of the casing of the experimental group rises, the heat dissipating layer 20 is efficiently helpful in dissipating heat.

Furthermore, in the above mentioned experiment, the heating device respectively heats the casings of the experimental group and the control group until the casings achieve their respective highest temperatures and the temperatures of the casings stop rising. When the casings of the experimental and control groups are heated, the heat is dissipated from the casings of the experimental and control groups simultaneously. Therefore, according to the highest temperatures and the heating times of the casings of the experimental and control groups, the heat dissipating effects of the casings of the experimental and control groups can be measured. As shown in Table 1, the highest temperatures of the casing of the experimental group range from 710.1° C. to 761.9° C. . The highest temperatures of the casing of the control group range from 867.7° C. to 906.2° C., which are higher than the highest temperatures of the casing of the experimental group. The heating times of the experimental group range from 23.88 min to 23.86 min. The heating times of the control group range from 12.55 min to 18.68 min, which are shorter than the heating times of the experimental group. The experiment demonstrates that it takes more time to heat the casing of the experimental group to allow the casing of the experimental group to achieve its highest temperatures than to heat the casing of the control group to allow the casing of the control group to achieve its highest temperatures, and the highest temperatures of the casing of the experimental group are lower than the highest temperatures of the casing of the control group. Therefore, the casing of the experimental group has better heat dissipating effect than the casing of the control group.

The casing of the turbocharger in accordance with the present invention has the following advantages. With the heat dissipating layer 20 disposed on the outer surface of the main body 10, 10A, when the heat inside the main body 10, 10A is conducted to the outer surface of the main body 10, 10A, the heat dissipating layer 20 dissipates the heat quickly. Since the heat does not accumulate in the main body 10, 10A, the temperature of the main body 10, 10A is low and the casing does not oxidize under high temperature. The heating dissipating layer 20 may be coated on the outer surface of the main body 10, 10A. Coating the heat dissipating layer 20 on the outer surface of the main body 10, 10A is easy and cost effective. Therefore, the casing of the turbocharger of the present invention has low manufacturing cost and is economical. Moreover, as each of the CNCs of the heat dissipating layer 20 is formed as a carbon sphere encapsulated in a hollow carbon sphere, structure of the CNC allows the CNC to have a good heat dissipating effect. Consequently, the heating dissipating layer 20 has improved heat dissipating effect.

Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A casing of a turbocharger comprising: a main body being hollow and having an outer surface; and a heat dissipating layer disposed on the outer surface of the main body.
 2. The casing of the turbocharger as claimed in claim 1, wherein the heat dissipating layer is coated on the outer surface of the main body.
 3. The casing of the turbocharger as claimed in claim 1, wherein the outer surface of the main body is rough.
 4. The casing of the turbocharger as claimed in claim 2, wherein the outer surface of the main body is rough.
 5. The casing of the turbocharger as claimed in claim 1, wherein the heat dissipating layer comprises multiple carbon nanocapsules (CNCs).
 6. The casing of the turbocharger as claimed in claim 2, wherein the heat dissipating layer comprises multiple carbon nanocapsules (CNCs).
 7. The casing of the turbocharger as claimed in claim 3, wherein the heat dissipating layer comprises multiple carbon nanocapsules (CNCs).
 8. The casing of the turbocharger as claimed in claim 4, wherein the heat dissipating layer comprises multiple carbon nanocapsules (CNCs).
 9. The casing of the turbocharger as claimed in claim 6, wherein an amount of the CNCs is 7 weight percent (wt %) of the heat dissipating layer.
 10. The casing of the turbocharger as claimed in claim 8, wherein an amount of the CNCs is 7 wt % of the heat dissipating layer.
 11. The casing of the turbocharger as claimed in claim 9, wherein a thickness of the heat dissipating layer is 20 μm to 80 μm.
 12. The casing of the turbocharger as claimed in claim 10, wherein a thickness of the heat dissipating layer is 20 μm to 80 μm.
 13. The casing of the turbocharger as claimed in claim 11, wherein a thickness of the heat dissipating layer is 50 μm.
 14. The casing of the turbocharger as claimed in claim 12, wherein a thickness of the heat dissipating layer is 50 μm. 